CardioExchange Archive

Although people with atrial fibrillation (AF) and people with chronic kidney disease (CKD) are at elevated risk for stroke and other vascular events, people with both conditions have not been well studied, since those with CKD have been excluded from most clinical trials of stroke prevention for AF. The problem is further compounded because the presence of CKD increases the risk for bleeding associated with anticoagulation.

Now, a large observational study from Denmark published in the New England Journal of Medicine provides new evidence to better estimate risk and to help determine a treatment strategy for patients with both AF and CKD. Jonas Bjerring Olesen and colleagues analyzed data from 132,372 Danish patients with AF and found 3587 who also had chronic CKD and 901 who received dialysis or a transplant.

Compared to patients with no renal disease, patients with CKD were at significantly elevated risk for stroke or thromboembolism, bleeding, MI, and death:

Stroke or thromboembolism (event rate per 100 person-years):

• No renal disease: 3.61
• Chronic CKD: 6.44
• CKD requiring renal replacement therapy: 5.61

Bleeding (event rate per 100 person-years):

• No renal disease: 3.54
• Chronic CKD: 8.77
• CKD requiring renal replacement therapy: 8.89

Myocardial infarction (event rate per 100 person-years):

• No renal disease: 1.88
• Chronic CKD: 5.81
• CKD requiring renal replacement therapy: 5.98

Death (event rate per 100 person-years):

• No renal disease: 11.21
• Chronic CKD: 38.65
• CKD requiring renal replacement therapy: 29.35

The investigators found that warfarin but not aspirin reduced the risk for stroke or thromboembolism in the patients with CKD. Both warfarin and aspirin were associated with an increased risk for bleeding, however. “Thus,” the authors wrote, “the net clinical effect of warfarin treatment requires careful assessment in patients with chronic kidney disease, and the data do not provide clear guidance regarding indications for anticoagulant therapy in patients with both atrial fibrillation and chronic kidney disease. Certainly, close monitoring of the international normalized ratio is required when warfarin is administered.”